Climate Change Impacts

Please note: Until the HUD Environmental Review Online System (HEROS) is updated to add a dedicated row for the Climate Change Factor on the environmental assessment (EA) Factors page of HEROS (page 4010), review preparers should report any Climate Change impacts and mitigation in the Other Factors row under the Natural Features EA category.

Overview

A proposed project should consider the likely impacts of climate change on the project’s short- and long-term suitability and resilience. Many natural systems are expected to be affected by climate change, so these considerations will be wide-ranging.

In fact, climate change’s interactions with natural disasters have already affected residents of HUD-assisted housing. Historic storms like hurricanes Katrina and Sandy have demonstrated the disproportionate impact these events have on residents of low-income housing. Therefore, HUD-assisted projects need to consider the potential future impacts of climate change on occupants. This applies to both new and existing structures; though climate impacts may not have been considered during a project’s initial environmental review, subsequent Environmental Assessment (EA)-level reviews (e.g., for major rehabilitations) should consider potential climate impacts on residents’ safety, wellbeing, and property.

The frequency and severity of natural hazards may be affected by climate change, including:

  • Flooding
  • Sea level rise
  • Hurricanes and extreme storms
  • Drought
  • Extreme heat
  • Wildfire
  • Landslides
  • Extreme cold (e.g., from “polar vortex” destabilization)

Similarly, climate change may alter site suitability factors, such as:

  • Air quality
  • Urban heat island effects
  • Soil stability
  • Water resources
    • Groundwater availability (e.g., water table level, reliance on a sole source aquifer)
    • Excessive stormwater runoff and site flooding
    • Wastewater control systems and water treatment facilities

Under Executive Order 14008 on Tackling the Climate Crisis at Home and Abroad, it is federal policy to incorporate climate considerations into decision-making and build resilience against the impacts of climate change. HUD-assisted projects should protect human health and the environment by ensuring they are prepared to withstand the impacts of climate change.

Important Considerations

Climate change impacts on the project:

  1. Is this project designed in a way that it will withstand, within the useful life of the project, the expected climate related changes projected for the area? Numerous resources, such as those listed later on this page, are available to help identify future climate threats. As a rule of thumb, the project’s mortgage length (often 30-40 years) can be used as a minimum, though the useful life of a building is often much longer.
  2. How will increasingly frequent or severe natural disasters affect the proposed project?
  3. What specific climate change impacts have been identified for the project area? What measures will help mitigate those impacts? Will they shorten the project’s lifespan?
  4. The effect of existing or ongoing local infrastructure projects designed to mitigate the impact of climate change may be considered; however, such projects do not eliminate the need to include mitigation measures specific to the proposed project.
  5. What future climate projections were considered when planning mitigation measures? If more extreme climate scenarios occur, how much of a margin of error will the project have?
  6. As you work through the other environmental assessment factors that focus on the natural environment (e.g., water resources, soil suitability, etc.), consider what the results of the analysis would be under moderate and severe future climate scenarios.
    • Do the results of any of these analyses change?
    • How will those likely future results affect the wellbeing of project residents and the natural environment?
      • For example, could heavier precipitation in the future cause stormwater runoff issues, despite the project site’s currently sufficient drainage?

Project contributions to climate change:

  1. How has the project plan reduced its direct contribution to climate change? Where feasible, consider using low-carbon building materials and incorporating existing buildings into the project to reduce greenhouse gas emissions from construction and material fabrication.
  2. Has the project considered indirect contributions toward climate change? For example, a project could provide electric vehicle charging infrastructure to reduce carbon emissions from residents’ transportation choices.
  3. What greenhouse gas emissions level targets were the proposed project’s sustainability tactics designed to meet?

Analysis Techniques

Weighing the influence of climate change will require responsible entities, recipients, applicants, and partners to anticipate future conditions that are liable to arise. Though this forward projection will inherently include uncertainty, a large and growing amount of research has been conducted on how climate change will impact natural systems and the human environment. Combining this research with the proposed project’s local context will allow the responsible entity, recipients, applicants, and partners to identify significant potential climate change impacts.

The first step is to understand the likely impacts of climate change in the project area. Many useful resources, like the U.S. Climate Resilience Toolkit, can help environmental review preparers consider climate change impacts at the local level. Then, the project can employ adaptation strategies, such as those found in the Environmental Protection Agency (EPA)’s Climate Change Adaptation Resource Center. Throughout the process, reviewers should consider the social vulnerability of the project’s residents and surroundings, using informative resources like EPA’s report on Climate Change and Social Vulnerability in the U.S. Additional valuable resources can be found on this webpage.

When using climate tools that project into the future, it is necessary to consider the range of potential future conditions possible. Using results derived from worst case scenario assumptions (e.g., high carbon emissions) can help plan for maximum resilience by building in a margin of safety. Conversely, using intermediate scenarios (e.g., lower emissions) may reduce up-front costs but expose the project to greater risk.

The scope of this analysis will depend on the project’s climate vulnerability and scale. For example, coastal areas are especially vulnerable to climate change impacts, such as more powerful hurricanes, so they will require more comprehensive analysis of these climate impacts. Likewise, context-specific mitigating actions will be needed to prioritize addressing the highest-threat climate impacts. Similarly, smaller projects like minor rehabilitations may require less intensive climate vulnerability analysis than larger projects, like new construction.

Mitigation Measures

For individual HUD-assisted projects, climate change mitigation measures may include adaptation and resilience tactics, as well as carbon emission reductions. The direct (e.g., utility use) and indirect (e.g., from increased vehicular traffic) greenhouse gas emissions from the proposed project should be considered and reduced where feasible.

In order to ensure the proposed project will be resilient to future conditions, responsible entities, recipients, applicants, and partners should consider future projections as well as current conditions on the project site whenever possible. Doing so will help account for the likely changes driven by climate change.

More specific measures will depend on the climate risks, local context, and nature of the proposed project. Adaptation and mitigation can be achieved through diverse strategies such as site selection and design, building design and construction practices, and institutional measures. For instance, a large multifamily residential structure that lies near a coastal floodplain may someday lie within the floodplain due to sea level rise. Considering the likely future extent of the floodplain could lead to a different site selection (if possible) or prompt ground-floor floodproofing (if the structure is already in place), protecting the project and its residents in the future. If choosing another site for a project is not possible, other adaptation measures will be even more important to ensure the safety and resilience of the project and its residents. Consult the following resources for more specifics.

Adopting mitigating measures and resilience tactics to account for future conditions during the initial stages of the project can help prevent future losses related to emergent conditions from climate change.